Smoother navigation bar UX to reduce flickering and missed clicks

In its current state, the dropdown menu on the navigation bar is prone to flickering, and it is sometimes hard to click the button you want to hit. If your cursor hovers just one pixel outside of the hitbox the menu disappears.

There are a few ways to solve this, from introducing a delay (with the issue that it creates lag) to smarter approaches that analyze mouse movement. Some more details and code examples can be found in this article: https://www.smashingmagazine.com/2021/05/frustrating-design-patterns-mega-dropdown-hover-menus/

首先复现 issue 中描述的导航栏下拉菜单行为，尤其是在光标刚好移到 hitbox 外部时的表现，并阅读链接的 Smashing Magazine 文章以了解交互背景。完成标准是：菜单在正常指针移动过程中不再闪烁或消失，并且其按钮可以可靠地点击。